Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) are widely used in communication systems. Herein, the FDD needs to use the uplink and downlink frequencies in pairs to take full advantage of uplink and downlink spectrums when supporting symmetrical services in which the voice service is a representative. However, in asymmetric services, in which the IP service is a representative, such as online video, software download, webpage browsing whose downlink speed is the key factor, the spectrum utilization is greatly reduced, the uplink spectrum resources are not used, and there is a phenomenon of the waste of uplink spectrum resources, therefore, how to effectively improve the spectrum utilization has become an urgent problem to be solved.